1. Field of the Invention
The present invention relates to a method for handover between heterogeneous networks using a link trigger signal in a multi-interface mobile router; and, more particularly, to an apparatus which can save power consumption of the mobile router, and prevent packet loss and cease of session with respect to fixed nodes included in a subordinate mobile network with no regard to a moving speed of a mobile router by performing handover between heterogeneous networks, in particular, between a terrestrial wireless network and a satellite network, using a link-up/down trigger signal in a multi-interface mobile router when a mobile network including a mobile router and the fixed node moves at high-speed.
This work was supported by the IT R&D program for MIC/IITA [2006-S-020-02, “Development of Satellite and Terrestrial Convergence Technology for Internet Service on High-speed Mobile Vehicles”].
2. Description of Related Art
According to generalization of a mobile internet service, a technology maintaining a service ceaselessly with respect to a connected session although a mobile network having a fixed node as a subordinate such as an express train as well as a mobile node moves between networks at high-speed is required.
In particular, a technology for handover between networks which can minimize packet loss and delay while using an IPv4-based mobile network in case of a high-speed mobile router moving at the speed of more than 300 Km/h such as an express train is required.
As a related art, there is a method for applying fast mobile IPv6 with respect to a mobile node while a mobile router performs handover. In this method, when the mobile router receives prefix information corresponding to a new access router after moving from an old access router before handover, and transmits the information to the mobile node, the mobile router and the mobile node request fast IPv6 binding update to the old access router.
When the old access router and the new access router exchange a handover initiate and acknowledgement message according to fast IPv6 binding and the old access router transmits a fast binding acknowledgement message to the mobile router and the mobile node, data toward the mobile router and node using the old prefix are transmitted from the old access router to the new access router through a tunnel.
When the mobile router receives the fast binding acknowledgement message and directly transmits a zero lifetime message for the old prefix release to the mobile node, the mobile node transmits data based on a new prefix.
Since the related art applies the fast mobile IPv6 described above, the mobile router can prevent packet loss in the duration of handover with respect to communication performed between the mobile node and a correspondent node (CN) and reduce a handover delay time.
However, there is a problem that since a high-speed moving object such as an express train running at a speed over 300 Km/h passes through a plurality of cells at high-speed due to a small mobile cell size, failure probability of handover increases and a minimal time required for handover between cells is not acquired to thereby cause packet loss.